Radio remote-control apparatus



Nov. 16,1948'.

M. N. YARDl-:NY

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i` 239 .PowER RECEIVER. :Supny E umT i? 25s 240 /06 257 RADIo mfom CONTROL Arwmus Filed Feb. 9, 1945 l 2 .sne'ets-sneei 2 Patented Nov. 16, 1948 UNITED STATES PATENT OFFICE RADIO REMOTE-CONTROL APPARATUS Michel N. Yardeny, New York, N. Y.

Application February 9, 1945, Serial No. 576,919

(Cl. Z50-2) 10 Claims.

This invention relates to remote control systems for controlling or energizing from a control point, a motor located at a remote point to place an object or load at any desired position.

One of the principal objects of the invention is to provide a remote control system of the character described in which the link between the control point and the remote point shall be solely by radio waves. An allied object is to provide a remote control system by which the load at a remote point may be moved in correspondence with the movement of a control member at the control point, without the use of wires or other connecting medium other` than the ether between the A further allied obcontrol and remote points. ject is to provide a remote control system in which the load motor at the remote point is controlled by radio waves originating at a transmitter at the control point and under guidance of a selec-l tively moved control member.

Another object of the invention is to provide a remote control system in which the said transmitter at the control point radiates two characteristically different radio waves, one for rotating the load motor at the remote point in one direction, and the other wave, for rotation in the opposite direction. An allied object is a remote control system in which the two said characteristically different radio waves diier in audio frequency.

Another object of the invention is to provide a remote control device in which the load motor at the remote point is controlled by radio waves originating at a primary control device at the control point, and in which the load motor, in turn, motivates a transmitter at the remote point to radiate radio waves (preferably characteristically ditferent from the said motivating radio Waves) which are sent back to the control point to energize instrumentalities for maintaining the movement of the primary control in precise correspondence of coordination with that of the load motor. An allied object is to provide a remote control system as just described in which the said characteristic diierence between the motivating and coordinating radio waves resides in a predetermined diiierence in their radio frequency (so not to cause interference between the two types of radio radiations). Another allied object is to provide a remote control system as here described v in which the said coordinating radio waves are varied or modulated in audio frequency with the changes in angular position oi a member driven by the load motor, and the varying A. F. modulated waves received at the control point to turn an element of the primary control device in correspondence with the said load motor-driven member at the remote point.

Another object is to provide a remote control system as here described which in normal functioning transmits a motivating radio wave from the primary control device at the control point to the load motor at the remote point and transmits back to the control point a coordinating radio wave, but which system may be conditioned to transmit a zeroizing radio wave from the control to the remote point for the purpose of resetting or zeroizing the system to check any deviation of the parts of the system from true correspondence.

For the attainment of these and such other objects of invention as may appear or be pointed out herein I have shown an embodiment of my invention in the accompanying drawings, wherein:

Fig. l is a diagrammatic showing of the radio remote control system of this invention; and

Fig. 2 is a diagrammatic showing of a portion of the system of Fig. l in which the pilot motor and pilot motor control device are replaced by a single instrumentality.

rThe remote control apparatus according to the invention includes a primary control device (designated generally at A in Fig. l) at a control point, comprising a pair of control members both rotatively mounted on a shaft I. One of the pair of members is an insulated disc 2, which may have gear teeth on its periphery, and which mounts two metal conducting segments 3, 4 insulated from each other and separated by gaps 5, 6.

' The other member of the pair is a contact arm l provided with a contact 8 slidably engageable with individual ones of the segments 3, 4 and adapted to bridge gap 5 or B to engage both segments simultaneously. Arm 'I is provided with a knob S for manual operation and with a pointer i9 for indicating the position of the arm on a stationary scale I5. Disc 2 likewise may have a pointer or index mark 36 also indicative on scale l5.

Segments 3, 4 are connected to collector rings, respectively, IB, l'l which are engaged by respective brushes IB, I9, connected by leads 29, 2| to one of the input terminals of a pair of audio irequency modulators 23, 24, respectively, which are provided to modulate the radio frequency waves at two different predetermined audio frequencies. The output terminals of the pair of modulators are connected to a single radio transmitter 22, supplied with a current from a power supply unit 25. The o-ther input terminals oi the pair of modulators are connected by common leads 24', 23 to Contact arm 'l'. Power supply unit 25 is connected to the two terminals 3@ and 35 of a source of current 3l, being connected to 'terminal 30 by leads i535 and iti leading to a contact H62 engageable by a switch arm 63, and through a switch 29; connection to the other terminal 35 is through leads 2l, ill and switch M35i. The transmitter 22 is grounded at 32 and is provided with an antenna 3? which radiates waves indicated by dashed line Sil. The waves are picked up at the remote point by an antenna 2l of a receiver di), grounded at d, and tuned to the radio frequency carrier wave of transmitter 22. The receiver is connected to a power supply unit 38, which is connected through short leads to supply wires lid and 4G leading to source of current 52.

Radio transmission units of the conventional type, such as are used in radio transmission of sound, may be employed in the improved remote control system oi the invention, including audio frequency modulators which are also adaptable to the radio `transmission of power impulses. The audio frequency modulation may vary either the intensity (amplitude) of the carrier-AM systemor the frequency of the carrier-FM system. Receiver Lili will pass both audio frequencies originating at modulators 23 and 25, at the control point. riwo band pass filters and Titi wired to receiver Lili, are each adapted to pass only the particular predetermined audio ire quency corresponding, respectively, to that of modulators 23, and 2d. rihe iiltered frequencies pass through audio frequency ampliiiers, respectively, 5l and 5B, the ampliiled output of which is conducted by paired leads 6l, 52 to respective ones of a pair or relays 59 and titl.

The armatures 59 and 6B of the respective relays 59 and Gil, joined by a common lead normally engage contacts, Gi, Gti on a lead fit connected to supply wire lil leading to terminal 4I of the source ft2. Although the motor shown is of the series wound type, it is to be understood that any other type of motor may be used. Relay armatures 59, Gil', uponthe energiaation of their respective relays, engage contacts till', S5', which are connected to the outer terminals oi respective iield windings Gli, tl; the inner terminals of the windings have a common lead to motor armature lill, circuit being continued through supply wire llt to the other supply terminal 48.

Motor $8 drives a load, diagrammatically represented at l5, through a shaft l5 and gears il, l. The primary control device A, load motor titi and associated parts are preferably, though not necessarily, designed s0 that contact arm 'i is turned in the same direction in which it is desired to move the load. Also7 the scale le may be marked in degrees of a circle, so that contact arm 'i may be turned to the particular angular position corresponding to the end position to which it is desired to move the load.

Supply switches 29, 85 are closed to place the system in operation, switch arm it being nor mally engaged with its contact M2 (as shown), furnishing current to power supply unit from source 3l and causing transmitter 22 to radiate carrier waves of a predetermined radio frequency, which is adapted to be modulated by one or the other of the audio modulators 23 and 2li when their respective circuits are closed, as will now be described. Assuming that it is desired to rotate load motor 68 to move the load clockwise, through a particular degree of a circle from a normal or zero position, to a desired end position, contact arm l' of the primary control device is turned clockwise, by hand or other instrumentalities, to an angular position, as indicated by scale l5, corresponding to the desired end position of the load. Engagement of contact B of the contact arm with conducting segment 4 will complete the circuit associated with modulator 2d, starting at lead 2t from the modulator and continuing through lead 23', contact arm l, collector ring El, brush i9, and through lead 2l back to modulator 24. IThis will cause the transmitter to radiate radio waves modulated by the predetermined audio fre v quency of audio modulator 24.

This wave will be picked up at the remote point by receiver 40, which is tuned to the radio irequency of transmitter 2 2 and will pass both audio frequencies originating at modulators 23, 24; the audio frequency modulation radiated by transmitter 22, in the operation being described, is blocked at band pass iilter 55 but admitted by lter 56 which, as already described, is designed to pass frequencies of the predetermined audio frequency of modulator 211; Audio ampliiier 58, associated with band pass lter 56, will amplify the admitted signal, using current from local source 42 for this purpose, more particularly, from power supply unit 38. The amplied cure rent will energize relay Sii to attract its armature lit" into engagement with its contact eil' and thus to complete a circuit through motor held winding 6E which may be traced from the supply terminal 4l, through leads M, 44', contact Bt of deenergized relay 59, unattracted armature 5t',

short lead 69, armature till of the other relay til (energized as described) through relay contact 55 to winding 61, the circuit continuing through motor armature ill and through lead 46 to the other supply terminal 48.

Concurrently with the rotation of motor the insulated disc 2 ci the primary control device A at the transmitting point. is turned in a direction to cause the gap 5 separating the conducting segments 3, ll, to overtake contact arm 1. For this purpose there is provided at the transmit ting point a pilot motor lll, shown of the type having a permanent eld magnet ili, which drives insulated disc 2 through shaft ils and pinion |86, which may be toothed or friction, meshing a gear (not shown) secured to rotate with disc 2. Pilot motor ITI` is caused to rotate in correspondence with load motor 68 at the remote point by means of coordinating means which includes a commutator device (designated generally at B) at the remote point and a pilot motor device (designated generally at C) at the control point, the two being coupled via radio V the distal end of commutator arm lill slidably engages a plurality of stationary contacts 85, 8l, and 88: 8G', El' and 88 disposed concentrically about shaft 89. Only two sets of three contacts each, i. e, set 8d, 8l' and Stand set 86', 8l and 38', are shown, for facility of illustration, aln though it will be clear that a greater number of sets may be employed and that the number of contacts in each set isnot necessarily restricted to three. The respective contacts of' each set 'are connectedy in' groups; contacts B6, 86 are connected by a lead 92; contacts 81, 81' by lead 93; contacts 88, 88', by lead 94. The said leads 92, 93, 94 are connected by leads, respectively, 95, 96, 91 to one input terminal of respective audio frequency modulators 98, 99 and |00. The other input terminals of the modulators are'connected by a common lead |04 and a lead |03 to the commutator arm Modulators 68, 99 and |00 are adapted to modulate the generated radio Waves at diierent predetermined audio frequencies-the radio frequency of which is different from that of the radio frequency radiating from transmitter 22 at the control point. The plurality of modulators are Wired to a common transmitter |05 having antenna |08 and grounded at |09, and Wired to power supply unit |06 which is connected by leads |01, lillX to current supply Wires 44, 46, respectively, leading to source 42.

The Waves radiated from antenna |08, indicated oy dashed line H0, are picked up at the control point by antenna of a receiver ||2, grounded at H3 and supplied with current from a power supply unit H4. Receiver ||2 is tuned to the radio frequency of transmitter |05 at the remote point and will pass all three audio frequencies originating at modulators 98, 99 and |00 at the remote point. Three band pass filters |5, ||S and H1 Wired to receiver H2, are each designed to pass only the audio frequency of the particular predetermined audio frequency correspending, respectively, to that of modulators 98, 99 and |00 at the remote point transmitter |05. The band pass lters are individually Wired to audio ampliers H5', |16 and ||1', which are individually connected to relays, respectively, I8, |9 and |20. Receiver ||2 is Wired to power supply unit ||4 which is connected by leads |25, |25 to supply Wires |64 and IBI, respectively, leading to source 3|.

The armature |26 of relay H8, when the latter is energized, engages relay contact |29 which is connected to a lead |36 terminating in stationary contacts |42, |42; armature |21 of relay H9, when energized, engages relay contact |30 connected to a lead |31 terminating in stationary contacts |43, |43'; armature |28 of relay |20 engages relay contact |3| connected to a lead |38 terminating in stationary contacts |44, |44'. The relay armatures |26, |21, |28 are connected by a common lead 85 to lead |25 connecting with supply wire |64 from supply terminal 35. The said stationary contacts are concentrically spaced about the shaft |46 of the pilot motor control C. Rotatively mounted on shaft |46 is an insulated disc |45 bearing a pair of conducting segments |41 and |48, the adjacent ends of which are separated by a gap |49, in sliding engagement with the aforesaid stationary contacts. Segment |41 is connected to a collector ring |50 engaged by a brush |52 connected by lead |54 to a relay |55; segment |48 is connected to a collector ring |5| engaged by a brush |53 connected by lead |55 to a relair |51. The other terminals of relays |56 and |51 are joined by Wire |60 which is connected by short lead |60X to Wire |6| which, as previously described, is connected to one terminal 30 of the current source 3| Armature |10 of relay |56, when the latter is deenergized, engages a contact lli.- connected to Wire |64 which, as previously described, is connected to the other supply tei'- minal 05, and, when the relay is energized, engages a contact |12 on supply Wire |6|. Armature |1| of relay |51, when the latter is deenergized, engages a contact connected to supply wire |64, and, when the relay is energized, engages a contact |13 on the other supply Wire |6|. The insulated disc |45 is turned by the pilot motor |11 by means of a gear |86 secured to turn With disc |45 and meshing with the pinion |85 on the pilot motor shaft I 19.

As already described, load motor 68 at the remote point is caused to rotate in the desired direction by moving contact arm 1 of the primary control device A at the control point into enh gagement with one or the other of the segments 3, 4. Rotation of load motor 68 Will cause commutator arm 0| of commutating device Bto turn correspondingly to successively engage the stationary contacts 86, 81, 88, 86', 8l', 83'. The circuit to a particular one of the plurality of modulators 98, 99, |00 will be completed by the engagement or contact |02 of commutator arm |0| with one or the other of the stationary contacts (i. e., 86 or 86', 81 or 81', 88 or 88') connected to that particular modulator. For example, if commutator arm |0| is at stationary contact 86, as shown in Fig. 1 (or at the companion Contact 86'), a circuit will be completed to modulator 99 `which may be traced from common modulator Wire |04 through lead |03 to commutator arm |0|, its distal contact |02, stationary contact 86 and through lead 95 to modulator 99. Modulator 99 Will then modulate the carrier waves generated by transmitter |05 to the predetermined audio frequency assigned to 99. The modulated waves will be picked up by receiver ||2 at the control point, and only that audio frequency will pass the band pass iilter IS Which is designed to pass signals of the audio frequency originating at modulator 99. The amplified current from audio amplier |6 associated with band pass filter I6 will operate its associated relay H9, attracting its armature |21 into engagement With relay contact |30, thus energizing the stationary contacts |43, |43' associated with relay 9 and band pass filter I i0, the cir-cuit being traced from supply terminal through Wires |64, |25 to the common armature lead 85 and to armature |21, engaged relay contact |30, lead |31 and finally to stationary contacts |43, |43'.

In the angular position of insulated disc shown in Fig. l, energization of stationary contacts |43, |43' will have no effect upon the pilot motor control relays and |51 because both contacts engage, in the position of disc |45 shown, insulated portions of the disc; more particularly, stationary contact |43 will be at the insulated gap |49 between conducting segments |41, |48. 1Hence :pilot motor |11 will not rotate when insulated disc |45 of the pilot motor control C and the contact arm |0| of the commutator B are in the position shown in Fig. 1. However, When commutator arm |0I is moved (by load motor 68, as already described) to engage its contact |02 with the next stationary contact 81 to energize the corresponding pair of stationary contacts |44, |44' of pilot motor control device C-by means of modulator |00 and transmitter |05 at the remote point land receiver ||2 and band pass lter ||1 and associated parts at the control point, as described above in connection with the energization of stationary contacts 43, |43' at C-a circuit will be completed through pilot motor corr. trol relay |51. This circuit is traced from the energized stationary contact |44, engaged con ducting segment |43 (as shown in Fig. l), its associated collector ring |5|, brush |53, lead |55, to relay |51 and through common lead |60 and short lead to supply line |6| leading to the 7 other supply terminal 3c. The other energized contact itil of .the pair lflll, M4 will have no effect since it engages merely the insulated portion of disc M5.

Energization oi relay ll will attract its armature Il! into engagement with relay contact |13, thus establishing a circuit through pilot motor lll from supply terminal through supply wire EBI, relay contact llt, attracted relay armature lll, motor armature llt, armature llt of the other and deenergized relay i5@ and relay contact l'iil (in the position shown in Fig. l), and to the supply wire it@ leading to the other supply terminal 35.

In the turning of commutator arm mi' from the Erst portion or station (show in Fig. 1) in which its contact E92 engages only stationary contact 85 to the next station in which its contact lili engages only stationary contact 81, the

commutator contact lili? will, before fully reaching the next station at Sl, engage both stationary contacts 86 and ill. This will cause energization of four stationary contacts at the pilot motor control device C, namely, contacts M3, |43 and Mil, Mil'. Energization of stationary contacts M3 and iflil will have no effect since they engage insulated portions of the disc M5; nor will the energization of brush M3 have any efect lwhile disc ll is in the position shown with brush lili? engaging insulated gap E139. However, in the turning of disc illli from the first station with gap MS at contact M3 (as shown in Fig. l) by the now energized pilot motor lll', the other conducting segment lill of the disc will become engaged by energized contact |43 (commutator contact lilii still bridging stationary contacts ll and 8l). The concurrent engaging of segments 48 and lill, with both energized contacts M4 and M3, respectively, will cause the energization of both relays lt, l5? with the result that their respective armatures H0, lll will be attracted into engagement with relay contacts |12, 13, both of which are on the same supply wire itl, thus disconnecting the circuit to the motor armature llt. Pilot motor lll will be stopped by dynamic braking in the eld oi the permanent magnet llt and no further rotation will occur until commutator arm lill is further turned (by the load motor, as described) to move its contact m2 out of engagement with stationary contact 8E. Thereat, contact lllS at pilot motor control C will be deenergized, thus breaking the circuit to relay lr'l. Since relay 57 remains ener- `gized, the pilot motor will again start rotation,

which will continue until gap lll@ reaches con tact |44, breaking the circuit to relay IEB.

Current is continued to be supplied to the load motor 68 as the 'commutator arm lill of commutating device B and insulated disc lit of the pilot motor control C are turning successively from one stationary contact to the next. This stepped advance of commutator arm and pilot motor control disc continues as insulated disc 2 oi the primary control A turns in a direction to overtake contact arm '1, until gap 5 separating conducting segments il rea-ches the contact arm, at which time load motor S8 will be stopped (in the manner already described hereinbefore) thus stopping commutatcr arm lill at the last en gaged stationary contact and stopping pilot mo tor control disc lfli with the gap |49 separating its segments lill, Hi8, at the stationary Contact corresponding to the last engaged stationary contact of the commutator.

Rotationof pilot motor Ill `will also turn insulated disc 2 of primary control A in a direction to cause gap 5 separating conducting segments 3, ll to overtake contact arm l. When this .overtaking occurs and Contact arm 'l bridges gap 5 to .engage both conducting segments 3, Il, the load motor 68 at the remote point will. be stopped, for the following reasons: Engagement of both segments 3 and i will complete the circuits to both audio frequency modulators 23 and 24 which will modulate the radio frequency at the two different predetermined frequencies assigned to the respective modulators. At the remote point, both band pass filters 55 and 56 will admit the two audio frequencies, that originating at modulator 23 being passed by nlter 55 and the audio frequency originating at 2t being passed by filter 55. Hence both load motor control relays 59 and G will be `energized to attract their respective armatures 59 and tt into engagement with relay contacts lll' and $5'. The circuit (through the field windings 66, 6l) to motor armature 'lll will be broken and the load motor stopped. in Fig. l, contact 8 of Contact arm l is shown of sumcient width to vbridge gap 5 and engage both segments 3, Il simultaneously (resulting in energization of both relays 59 and lili at the remote point, as just described). `Similar results may be obtained by increasing the width of gap 5 and/cr decreasing ythe width oi contact 3, so that when the Contact arm l is aligned with the gap, its contact S will engage neither one of segments 3, 4. In this case, the circuit to both audio frequency modulators and 24 will be broken so that no modulation is imposed on the radiated waves. Hence there will be at the remote point no audio frequency waves to pass the band pass filters to energize load motor control relays 5S, til which remain deenergized, their respective armatures 59', G engaging relay contacts 84, 65 (as sho-wn in Fig. 1) ,to break the circuit to the load motor.

In the event that the concurrent movements of the load at the remote point and the contact arm 'l of primary control A are occasionally disarranged from true correspondence, an auxiliary coordinating load is provided for checking or resetting the position of the load to precisely correspond to a predetermined position of the contact arm l', such for instance, as to the Zero position of pointer it on scale i5. An independent auxiliary control system (which may be conveniently termed the zeroizing system in contradistinction to the main or coordinating system) for this purpose comprises a separate transmitter at the control point and a separate receiver at the remote point for controlling the load motor independently of the main control system described above. The Zeroizing transmitter at the control point, designated 200 in Fig. 1, vprovided with antenna 2M and grounded at 20,2, radiates lwaves of a predetermined radio frequency different from those of coordinating transmitters 22 associated with the primary control A at the control point and lll5 associated with Athe commutating device B at the remote point, so not .to cause interference therewith. Current is furnished to zeroizing transmitter 2M) from power supply unit |95 through paired leads 49, and is wired to an audio frequency modulator M39 which is in turn wired to the power supply unit i535; audio frequency modulator l99 is adapted when the circuit thereto is completed, as will be described, to modulate `the radio frequency waves. Power supply unit 195 is connected to supply -wire 4Hill leading to supply terminal 35 at current source 3|; the other supply terminal 30, however, is not directly connected to power supply unit |95 but is normally broken at a zeroizing switch |63. Switch arm |63 normally engages Contact |82 (shown in Fig. 1); to complete the supply circuit from terminal 39 to supply wire |S| which furnishes current to the various parts of the coordinating system (as already described), and is normally disengaged from its other contact |98 is at one end of wire |91 leading to power supply unit |95. Only when zeroizing switch |63 is moved from its normal position (shown in Fig 1) into engagement with contact |98 are the zeroizing transmitter 200 and modulator |99 made operative to radiate the modulated radio wave, for purposes more fully described subsequently.

The modulated waves radiated by zeroizing transmitter 290, and diagrammatically indicated by dashed lines 20|', are picked up by the antenna 294 of a zeroizing receiver 293 at the remote point, grounded at 295 and powered from a supply unit l29E connected by leads 201 and 39 to the supply terminals of local current source 42. Associated with receiver 203 is a band pass filter 299 to pass only the audio frequencies originating at A. F. modulator |99 of zeroizing transmitter 289 at the control point and picked up by zeroizing receiver 203 which is tuned to the predetermined radio frequency of the zeroizing transmitter 200. The A. F. signals are amplified at 2| 0, the amplied current being conducted by paired leads 45 to the coil 2|5 of a solenoid, the armature 2| 1 of which carries Contact 2|1 at its lower end. Contact l2|1X is engageable when the solenoid is energized, with conducting segments 225, 226 mounted on an insulated disc 228 separated by gap 221. Segment 225 is connected to collector ring 229 engaged by brush 23| which is connected by a lead 233 to the outer terminal of eld winding 61; segment 229 is connected to collector ring 230 engaged by brush 232 which is connected by a lead 234 to the outer terminal of the other iield winding S6. Solenoid armature 2|1 is connected by a flexible lead 2|8 and lead 2|9 to the current supply line 44. Insulated disc 228 is provided with a gear (not designated) meshing with pinion 11 on shaft 15 of load motor 68, so that disc 228 is turned concurrently with rotation of the load motor.

The rst step in zeroizing is to place contact arm 1 of primary control A in a position arbitrarily predetermined as the resetting or zeroizing position, preferably the zero position on scale |5. a position with the gap 5 separating conducting segments 3, 4 in alignment with Contact arm 8 at zero position, the engagement of contact 8 of arm 1 with one or the other of the segments will cause rotation of load motor 68, arm of commutating device B, disc |45 of pilot motor control C, pilot motor |11 and disc 2 of primary control A (in the manner described above) until gap is bridged by Contact 8, both the contact arm 1 and disc 2 then being at the zero position. Rotation of load motor 68 will also turn insulated disc 228 of the zeroizing system. If the load is correctly coordinated with primary control A, insulated disc 228 will be in the position in Fig. 1 with gap 221 at solenoid contact 2|1X, which is the zero position corresponding to zero position of primary control A.; the load, being operatively connected to disc 228 (by the transmission gearing described above), will likewise be at zero position. To rectify the If insulated disc 2 is not already in coordination between zeroizing disc 228 (and load 19) and the primary control A, and to be certain that disc 228 is at Zero position, Zeroizing switch |53 is moved from its normal or coordinating position (as shown in Fig. 1) into engagement with contact |98 to motivate the zeroizing system. This will close the branch of the power lines to power supply unit connected to supply terminal 39 via lead |91 and zeroizing switch |63. The other branch to power supply unit |95 via lead |54 already being completed, current will be thus furnished to transmitter V20E? and A, F. modulator 99, resulting in the radiation of audio modulated waves of the predetermined radio frequency to be picked up at the remote point by zeroizing receiver 293 and of the predetermined audio frequency to be admitted by band pass filter 299.

The aeroizing radio transmission picked up at the remote point by receiver 293 and passed by nlter 209 is amplied by audio amplifier 2|9 The amplied current is conducted by leads 45 to coil 2id or" the solenoid causing its armature 2|1 to move towards the conducting segments 225, 229 of insulated disc 22S and engaging its ccntact 2|1 therewith. It disc 228 happens to be in the zero position (as shown in Fig. 1) solenoid contact 2li will engage both conducting segments 225 and 226, and will cause energize,- tion of both field windings 91 and 95, respectively. The circuit to eld winding 61 may be traced from supply terminal 4| of the local source 42 via wire lid, lead 25S, solenoid Contact 2|1X, segment 225, its collector ring 229 and brush 23|,

lead 233, to winding B1, through motor armature 19 and wire llt baci; to the other supply terminal 48. The circuit to the other field winding 5S may be traced from its associated segment 226, collector ring 299 and brush 232; lead 234 to winding 9b, and through motor armature 18 back to supply terminal 4S in the manner described above relative to its companion winding 91. By reason of the energization of both neld windings 59 and S1, motor 19 will remain stationary and will not disturb the correct zero position of the load. If, on the other hand, gap 221 happens to be displaced from aero position (shown in Fig. 1) with solenoid contact 2|1 engaging only one of the segments 225, 22E, only that one of the windings |36, 61 associated with the engaged segment will be energized to cause the load motor to rotate and turn disc 228 in a direction to cause gap 221 to arrive at the solenoid Contact 221X (zero position) whereat motor 59 is stopped, as described above. Zeroizing switch |53 may then be restored to normal position (shown in Fig. 1) readying the system for regular coordinating operation.

In the arrangement of Fig. l, pilot motor |11 is employed for turning insulated disc 2 of primary control A and insulated disc |45 of pilot motor control device C. Both the pilot motor and its control device C may be combined in a single unit which serves the dual purpose oi turning disc 2 of primary control A and at the same time cooperating with commutator B in the coordinating operation. This is shown in Fig. 2 where the primary control A of Fig. 1 is duplicated, its component parts (and operation) being unchanged and bearing the identical reference characters of Fig. 1. The single unit, which is in effect a step-by-step actuator, designated generally at D, comprises a rotor 289 secured to shaft |19 which turns insulated disc 2 in the manner, and for the purpose, described above in connection with Fig. i. Rotor 2tlg has permanent N and S poles, as shown, andI is caused toturn by the successive energization (in a manner subsequently described) ofA a plurality of magnet coils Ztl, 282, 233, 231i, 285i and 28i concentrically spaced about rotor 259. One termi nal of the coils is connected to a common lead 281 connected by lead 283 to supply wire ll leading to supply terminal 3B; the other ends of the coils are connected byindividual leads, reH spectively, 2li, 212, 213, 215i, 275 and 2l@ tothe respective contacts 251i, 262, 263, 264, 265 of the plurality of relays 25! to 253. The armatures, designated 25W, 25W, 251.3%, 254W, 255X, 256x, of the relays are connected -toa common lead 26E? joined to supplywire it leading to supply terminal 35, and are normally, i. e., when their respective relays are deenergized, engaged with blind contacts (as shown). energized condition of the relays (as shown in Fig. 2), the circuits to the plurality of magnet coils 28l to Ztl will be broken at the relay armatures. For the purpose of venergizing the relays 25! to 255, each is individually wired to respective ones of a plurality of audio frequency amplifiers 24V, 2052', etc. to 2135 which are in turn individually wired to respective ones of a plurality of band pass iilters 2M, 262, etc. to l. The plurality of filters are wired to a common receiver 240 provided with an antenna 239 and grounded at 23S. Receiver 2t@ and the plurality of band pass filters and AF'. ampliiiers are powered from power supply unit 23l connected by leads N54 and lili to the current source Si.

l Receiver 24U is tuned to the radio frequency of transmitter HB5', at the remote point. Associated With the transmitter are a plurality of AF. modulators 225 to 23u, inclusive, equal in number to the number of band pass iilters 2li! to 246 at the control point. The plurality of modulators are controlled by a commutating device B having a number of stationary contacts 23! to 236, inclusive, equal to the number of modulators (and band pass filters). The stationary contacts are not grouped or paired as is the case in Fig. l, but each commutator contact is individual to a particular modulator'. The plurality of modulators 225 to 230, inclusive, are arranged to modulate the radio frequency waves at dif ferent predetermined audio frequencies corresponding to the audio frequencies admitted by corresponding ones or" the plurality of band pass filters 24| and 265i associated with step-by-step actuator D at the control point.

Commutator arm lili of the commutator device B. is turned (by load motor 68 in the manner described in connection with Fig. l) to successively engage the plurality of stationary contacts 23| to 23B, inclusive, and thus to close the circuits 15o-successive ones of the plurality of A. F. modulators 225 to 23u, inclusive, resulting in the modulation of the radio wave generated by transmitter |05 at successively dierent predetermined audio frequencies. The modulated wave is picked up by receiver Mil but is blocked by the plurality of band. pass filters Elli to 246 except the particular oneassigned to the audio frequency of the modulator at the remote point associated with that particular stationary contact of commutator B which is engaged by commutator arm at the given instant. The audio frequency admitted by successive ones of the band pass filters 24J- 246, after being amplied, will energize relays 25 l-256 in succession. If, for example, the audio fre- Hence in the de l 12 quencyot the received wave at av given Ainstant corresponds to ythat to which band pass lter 245 is assigned-the A. F. modulation will be admitted by 21H, will be amplified by 2M and will energize relay 25, which will attract its arm 25H X into en gagement with relay contact 26! to complete the circuit to magnet coil 2N. 1llhis circuit may be tracedfrom supply terminal 35, through supply wire Mill and common relay lead 20fto relay armature 251x and engagedcontact 26i, through lead 2'll and; magnet coil 281 to common magnet coil lead and by lead 288 to supply wire ll leading to theotlier supply terminal 36. Energie :ration .of magnet coil 28!v will attract rotor 2853 towards it, ina counterclockwise sense asviewed in Fig. 2. As the magnet coils 28! 110.28@ (and 286 to 28E, repeating the steps) are successively energized-in correspondence with the ro-tation, counter-clockwise, of commutator arm lili, Fig. lrotor 28S will turn counter-cloclrwise in correspondence with the successive energization of magnet coils 28E- 286 and likewise in correspondence with the commutator arm lili and the load. Becauseof the drive connection H9, 180, betweenvthe kstep-byestep actuator D and insulated discf of-primary control A, disc 2 will turn in correspondence with the load. The radio link between B at the remote poin and the pilot motor control C at the control point shown in Fig. l, vand has been described, as a radio frequency `wave having interrupted or dis continuous modulation. This is occasioned by the fact that,ior facility in illustration and eX- position, the device at B was shown and described as commutator. That is to say, the modulation will be interrupted during the time that the com1 mutator arm disengages one stationary commun tator contact and before it has engaged the ynext successive contact. The invention, however, is in noway limited to the employment of a radio frequencywave having discontinuous modulations linking Band C, but contemplates that the modulation may be continuous as welles `disconr tinuous.. The continuous modulated radio waves, like thediscontinuous modulators imposed by the commutator, will be in repeated frequencies or patterns, originating at B and admitted by individual ones of the bandpass iiiters liti, H6,

l il at C in succession, so that their respective relays H8; EES, i2@ and associated stationary contacts M2, M3, EM, etc. will be successively en ergizedin correspondence with the transmitu ting device at B (likewise with the load motor and load).

l. In a remote control systemcontrolled from a control point to movea load at a remote point to any desired` end position, in combination, a primary control device at the control point comprising a pair2 oi relatively movable members, oneof the members having, electrical conducting elements separated bya gap, the other member having a contact element slidably engageable with the said conducting elements, a radio transmitter adapted to radiate waves of a predetermined radio frequency, a pair of audio frequency modulators, each modulator being connected in a circuit with the transmitterand in a second circuit with a ree spective one of the said conducting elements each modulator being. constructed and connected to modulate the saidradiated waves to a different predetermined audiofrequency, one of the said pair of members being selectively adjustable relative to the other member to cause displacement 13 between said gap and contact element and engagement thereof with one or the other of the said conducting elements to complete the second circuit to the respective one of the said pair of modulators depending upon said desired direction of load mo-vement; a reversible motor at the remote point for moving the load, a radio receiver adapted to pick up the radiated Waves of said predeter-mined radio frequency and to pass both said audio frequency modulations; a pair of band pass lters electrically connected to the receiver, each adapted to admit one of the two said predetermined diiferent audio `frequencies; a pair of relays controlling a circuit including the load motor, each relay being controlled by the corresponding filter to cause the load motor to rotate in the direction corresponding to the particular audio frequency being radiated; a commutating device comprising a pair of members one movable relatively to the other, one of the members having a plurality of contacts, the other member being a contactor slidably engageable with the said contacts, one of the said members being operatively connected with the load motor for causing successive engagement between the said member and said plurality of contacts, a second radio transmitter at the remote point adapted to radiate Waves of a radio frequency different from that radiated by the said primary control transmitter at the control point, a plurality of audio .frequency modulators connected in circuits with predetermined ones of the said commutator contacts and adapted to modulate the said radiated Wave at predetermined audio frequencies, each modulator being energized by the engagement of the respective commutator contact by the said contactor; a secondary control device at the control point including a pilot motor for turning the other cf the said pair of relatively movable members of the primary control device in a direction to cause alignment of Contact element and the said gap to cause both first mentioned modulators to transmit simultaneously their respective frequencies for causing both relays to be simultaneously energized, thereby stopping the load motor, said secondary control device comprising a pair of members one movable relatively to the other, one of the members having a plurality of contacts, the other member having electrical conducting elements separated by a gap, a second radio receiver adapted to pick up waves of the said predetermined radio frequency radiated by the transmitter at the remote point and to pass said plurality of predeterminedly differr ent audio frequencies, a plurality of band pass lters electrically connected to the second receiver. each filter being adapted to admit one of the audio frequencies transmitted by said plurality of modulators and connected in circuits with predetermined ones of the said pilot motor control device contacts to energize respective ones of the last-named contacts depending upon the particular audio frequency radiated by the commutator transmitter at the remote point, whereby the conducting element engaging one of the said last-named energized contacts causes the pilot motor to be energized, the pilot motor being operatively connected for turning one of the said pilot control members in a direction to cause alignment between said gap and energized contact to stop the pilot motor and the said member of the secondary control device with the gap at a position coordinated with the position of en- 14 gagement between commutator contacter and contact at the remote point,

2. In a remote control system controlled from a control point to move a load at a remote point to any desired end position, in combination, a primary control device at the control point cornprising a pair of relatively movable members, a radio transmitter adapted to radiate Waves of a predetermined radio frequency, a pair of audio frequency modulators connected in circuits with the transmitter and in second circuits With said members,` each modulator being constructed and connected to modulate the said radiated Waves to a different predetermined audio frequency, one of the said pair of members being selectively adjustable relative to the other member to complete one of the second circuits to one or the other of the said pair of modulators depending upon said desired direction of load movement; a reversible motor at the remote point for moving the load, a radio receiver adapted to pick up the radiated Waves of said predetermined radio frequency and to pass both said audio frequency modulations, a pair of band pass filters electrically connected to the receiver, each lter being adapted to admit v one of the tWo said predetermined different audio iii frequencies, a pair of relays controlling a circuit including the load motor, each relay being controlled by the corresponding filter to cause the load motor to rotate in a direction depending upon the particular audio frequency being radiated, a commutating device having a movable member driven by the load motor, a second radio transmitter at the remote point adapted to radiate Waves of a radio frequency different from that radiated by the said primary control transmitter at the control point, a plurality of audio frequency modulators connected in circuits with the second transmitter and adapted to modulate the said radiated wave at predetermined audio frequencies depending upon the position of the said movable member of the commutator device; a secondary control device at the control point having a movable member and including a pilot motor for turning the other of the said pair of relatively movable members of the primary control device in a direction to cause both first mentioned modulators to function and stop the load motor, a second radio receiver adapted to pick up the Waves of the predetermined radio frequency radiated by the transmitter at the remote point and to pass said plurality of predeterminedly different audio frequencies, a plurality of band pass lters electrically connected to the second receiver, each filter being adapted. to admit one of the audio frequencies transmitted by said plurality of modulators, to control in cooperation with the movable member of the secondary control device rotation of the pilot motor. the pilot motor being operatively connected to the said movable member of said pilot control device to stop the pilot motor at a position coordinated with the position of the said movable member of the commutator device at the remote point.

3. In a remote control system controlled from a control point to move a load at a remote point to any desired end position, in combination, a primary control device at the control point, a radio transmitter adapted to radiate Waves of a predetermined radio frequency, a pair of audio frequency modulators connected in a circuit with the transmitter and in a second circuit with the primary control device, each modulator being constructed and connected to modulate the said radiated Waves to a different predetermined audio frequency, the primary control device being selec tively adjustable to complete the circuit to one or the other of the said pair of modulators, drive means including a motor at the remote point 'for moving the load, a radio receiver adapted to pick up the radiated waves of said predetermined radio frequency and to pass both said' audio frequency modulations, a pair of band pass iilters each adapted to admit one of the two said predetermined different audio frequencies and electrically connected to the receiver; a pair of relays controlling a circuit including the load motor, each relay being controlled by the corresponding filter, to cause the load motor to rotate in a direction depending upon the particular audio frequency being radiated; a commutator control device at the remote point operatively connected to the load motor, a radio transmitter at the remote point adapted to radiate waves of a radio irequency diiierent from that radiated by the said primary control transmitter at the control point, a plurality of audio frequency modulators connected in circuits with the commutator control device and adapted to modulate the said radiated wave at predetermined audio frequencies depending upon the position or' the commutator control device at the remote point; a pilot control device at the control point including a pilot motor, a second radio receiver at the control point adapted to pick'. up the waves of the predetermined radio frequency radiated by the transmitter at the remote point and to pass said plurality of predeterminedly different audio frequencies, a plurality of band pass filters electrically connected to the second receiver, each lter being adapted to admit one of the plurality of audio frequencies radiated by the said transmitter at the remote point to control rotation of the pilot motor, the pilot motor being operatively con nected to the said pilot motor control device and to the said primary control device to stop the drive means at the remote point with the load in the desired end position'.

e. A remote control system having coordinating instrumentalities according to claim 3, further provided with Zeroizing instrumentalities comprising a radio transmitter at the control point adapted to radiate waves of a predetermined radio frequency different from that oi the said primary control transmitter and the said transmitter at the remote point, an audio modulator connected in circuit with the transmitter and adapted to modulate the said radiated waves at a predetermined audio frequency, a switch at the control .point for selectively `connecting a source of current to the coordinating instrumentalities or to the said zeroizing transmitter and modulator, the said switch being manipulated preparatory to zeroizing to connect the source of current to the coordinating instrumentalities at the control point and the primary control device being adjusted to a predetermined zero position, whereby the motor at the remote point is caused to rotate for moving the load to reach the corresponding zero position, whereafter the switch is manipulated to supply current to the zeroizing transmitter and modulator, the said zeroizing instrumentalities further comprising a radio receiver and bank pass filter connected in circuit thereto at the remote point adapted to piclr up and pass waves radiated by the said Zeroizing transmitter at the control point, a zeroizing device having a movable member provided with a pair of electrical conducting elements separated by a gap, the said conducting elements being connected in circuit with the motor to cause rotation of the same in respectively opposite directions, a con tact engageable with the said conducting elements, the load mot-or being operatively conn nected to the said movable member to move the same in a direction. to cause alignment between said gap and contact, and electromagnetic means actuated by the said audio modulated waves to engage the said contact with the conducting elements to supply current to the load motor, whereby the load and the said movable member oi the zeroizing device are turned until the said gap reaches the said engaged contact, thereby causing stopping of the load motor with the load at zero position.

5` A remote control system having coordinating instrumentalities according to claim 3, iurther provided with zeroizing instrumentalities c-omprising a radio transmitter at the control point adapted to radiate waves of a predetermined radio frequency diierent from that of the said primary control transmitter and the said transmitter at the remote point, an audio modulator connected in circuit with the transmitter and adapted to modulate the said radiated waves and band pass iilter at the remote point adapted to pick up and admit waves radiated by the said Zeroizing transmitter at the control point, and a zeroizing device having two relatively movable members electri cally and operatively connected to the load motor and actuated by the said audio modulated waves, the relative position of said members causing the motor to move the load to the aero position and to stop the motor when the members reach a predetermined relative position.

6. In a remote control system controlled from a control point to move a load at a remote point to any desired end position, in combination, a primary control device at the control point, radio transmitter adapted to radiate waves ci a predetermined radio frequency, a pair oi audio frequency modulators, each modulator being connected in a circuit with the transmitter and adapted to modulate the said radiated waves to a different predetermined audio frequency, the priu mary control device being selectively adjustable to complete the circuit to one or the other of the said pair of modulators; a reversible motor at the remote point for moving the load, a radio receiver adapted to pick up the radiated waves of said predetermined radio frequency and to pass both said audio frequency modulations, a pair ci band pass filters electrically connected to the receiver and each adapted to admit one of the two said predetermined different audio frequencies, means controlled by the filters for causing the load motor to rotate in a direction depending upon the particular audio frequency lbeing radiated; an adjustable secondary control device at the remote point operatively connected to the load motor, a second radio transmitter at the remote point adapted to radiate waves of a radio frequency different from that radiated by the said primary control transmitter at the control point, a plurality of audio frequency modulators connected in circuit with the second transmitter and in a second circuit with said secondary 4control device, said last-named modulators being adapted to modulate the said radiated wave at predetermined audio frequencies depending upon the position of said adjustable control device; a control motor at the control point for operating the said primary control device to cause both of its said pair oi modulators to function and stop the load motor', said -control motor having a magnetic rotor operal 7 tively connected to the said primary control device and a plurality of coils spaced about the said rotor, a second radio receiver adapted to pick up the waves of the predetermined radio frequency radiated by the transmitter at the remote point and to pass said plurality of predeterminedly different audio frequencies, a plurality of band pass filters connected in circuit with the second receiver and each adapted to admit one of the plurality of audio frequenciesradiated by the said transmitter at the remote point, a plurality of relays individually associated with respective ones `of the said plurality of band pass filters and respective ones of the said plurality of coils, said coils being adapted upon functioning of their respective band pass filters and relays to create a rotating magnetic field to cause rotation of the said rotor in coordination with the rotation of the said load motor.

'7. In a remote control system controlled from a control point to move a load at a remote point to any desired end position, in combination, a primary control device at the control point, a radio transmitter adapted to radiate Waves of a predetermined radio frequency, a pair of audio frequency modulators, each modulator being connected in a circuit with the transmitter and adapted to modulate the said radiated Waves to a different predetermined audio frequency, the primary control device being selectively adjustable to complete the circuit to one or the other of the said pair of modulators; a reversible motor at the remote point for moving the load, a radio receiver adapted to pick up the radiated Waves of said predetermined radio frequency and to pass both said audio frequency modulations, a pair of band pass filters electrically connected to the receiver and each adapted to admit one of the two said predetermined different audio frequencies, means controlled by the filters for causing the load motor to rotate in a direction depending upon the particular audio frequency being radiated; and adjustable secondary control device at the remote point operatively connected to the load motor, a second radio transmitter at the remote point adapted to radiate Waves of a radio frequency different from that radiated by the said primary control transmitter at the control point, a plurality of audio frequency modulators connected in circuit with the second transmitter and in a second -circuit with said secondary control device, said last-named modulators being adapted to modulate the said radiated wave at predetermined audio frequencies depending upon the position of said adjustable control device; a control motor at the control point for operating the said primary control device to cause both of its said pair of modulators to function and stop the load motor, said control motor having a magnetic rotor operatively connected to the said primary control device and a plurality of coils spaced about the said rotor, a second radio receiver adapted to pick up the Waves of the predetermined radio frequency radiated by the transmitter at the remote point and to pass said plurality of predeterminedly different audio frequencies, a plurality of band pass filters individually connected in circuits with respective ones of the said plurality of coils and each adapted to admit one of the plurality of audio frequencies radiated by the said transmitter at the remote point to create a rotating magnetic field at the said coil to cause rotation of the rotor in coordination with the rotation of the said load motor.

8. In a remote control system controlled from a control point to move a load at a remote point to any desired end position, in combination, a radio transmitter at the control point adapted to radiate waves of a predetermined radio frequency and two predetermined audio frequencies, a primary Control device at the control point electrically connected With the transmitter and selectively adjustable to modify the said radiated waves to one or the other of said audio frequencies, a motor at the remote point for moving the load, a radio receiver at the remote point adapted to pick up and selectively pass the radiated Waves, means connected with said receiver and responsive to the passed audio and radio frequency wave for causing the load motor to rotate in a direction depending upon the said Wave modification at the control point, a second radio transmitter at the remote point adapted to radiate Waves of a radio frequency different from that radiated by the said primary control transmitter at the control point, and of predetermined audio frequencies, a movable control device at the remote point electrically connected with the sec-ond transmitter and operatively connected to the load motor, said movable control device being adapted to modify the said radiated Wave, a second radio receiver at the control point adapted to pick up the Waves radiated by the transmitter at the remote point, a pilot motor operatively connected With the primary eontrol device for adjustment thereof, and means at the control point responsive to the output of the second receiver to energize the pilot motor to coordinate the said primary control device in accordance with the said wave modification at the remote point.

9. In a remote control system controlled from a control point to move a load at a remote point to any desired end position, in combination, instrumentalities including a radio transmitter at the control point adapted to radiate Waves of a predetermined radio frequency modified depending upon the desired load movement, a motor at the remote point for moving the load, instrumentalities including a radio receiver at the remote point adapted to pick up the radiated Waves and move the load motor in accordance With the said Wave modification at the control point, instrumentalities including a movable control device operatively connected with the load motor and also including a radio transmitter at the remote point adapted to radiate Waves of a radio frequency different from that radiated by the said transmitter at the control point as modifie-d by the movable device in dependence on the said load movement, and instrumentalities including a control motor operatively connected with the first instrumentalities and also including a radio receiver at the control .point adapted to pick up the Waves radiated by the transmitter at the remote point to control the control motor for coordinating the first instrumentalities at the control point with the load at the remote Ipoint in accordance with the said Wave modification at the remote point.

l0. In a remote control system controlled from a control point to move a load at a remote point to any desired end position, in combination, nstrumentalities including a radio transmitter at the control point adapted to radiate waves having selected characteristics modified depending upon the desired load movement, a motor at the remote point for moving the load, instrumentalities including a radio receiver at the remote point adapted to pick up the radiated Waves and move the load motor in accordance with the said Wave modification at the control point, instrumentaliti-es including a movable control device operatively connected with the load motor and also including a radio transmitter at the remote point adapted. to radiate Waves having characteristics diierent from that radiated by the said trans-- mitter at the control point as modified by the m vable device in dependence on the said load movement, and instrumentalities including a control motor operatively connected with the first instrumentalities and also including a radio receiver at the control point adapted to pick up the Waves radiated by the transmitter at the remote point to control the control motor for coordinating the first instrumentalities at the control point with the load at the remote point 10 Number in accordance with the .said .Wavermodicat'on at the remote point.

MICHEL N.' YARDENY.

REFERENCES CITED The following references are of record in' the file of this patent:

UNITED STATES PATENTS Name Date '714,862 Buck Dec. 2, 1902 1,597,416 Mirick Aug. 24, 1926 1,600,204 Alexanderson Sept. 14, 1926 2,165,800 Koch July 11, 1939 2,397,088 Clay Mar. 26, 1946 

